Overloaded Eccentrics: The Science, Benefits, and Practical Applications
Key Points:
Eccentric training (overloading the lowering phase of a movement) has been shown to increase strength and hypertrophy more effectively than traditional resistance training.
Neuromuscular adaptations from eccentric training include greater force production and unique muscle architecture changes.
Practical considerations: Overloaded eccentrics require specialized equipment or creative programming to implement safely.
Potential drawbacks: Eccentric training often leads to greater muscle damage and soreness, which may impact recovery and training frequency.
Introduction
Traditional resistance training has long been a cornerstone of strength and hypertrophy programs, focusing on balanced concentric (lifting) and eccentric (lowering) movements. However, research suggests that overloading the eccentric portion of a lift—which takes advantage of the body's ability to handle more weight while lowering—may lead to superior strength and muscle growth adaptations.
At Verro, we've recently acquired a Voltra 1 from Beyond Power, a tool that allows for precise eccentric overload. I’ve been experimenting by lifting weights I can handle concentrically but overloading the eccentric phase by an additional 25%. The results so far have been more effective than expected, prompting a deeper dive into the science behind eccentric training. Before implementing it more widely with clients, I wanted to review what the research says about eccentric overload compared to traditional strength training for both strength and hypertrophy.
Summary of the Research
STRENGTH ADAPTATIONS
Eccentric training has been shown to increase maximal strength more effectively than traditional resistance training over the course of a resistance training program. Studies from Hortobágyi et al. (2001) and Tøien et al. (2018) indicate that eccentric-focused protocols result in higher force production (12-18% increase) and greater neuromuscular efficiency in subjects with at least six months of prior training experience (1)(2). Walker et al. (2016) found that strength-trained individuals who used accentuated eccentric loading saw an 18-28% greater increase in maximum isometric and isokinetic force production over a 10-week period compared to traditional isoinertial training (3).
It's worth noting however that Tøien found no additional benefit to efferent neural drive from eccentric overload beyond traditional maximal strength training, suggesting that while strength gains are apparent, neural adaptations may not differ significantly from conventional heavy lifting (2).
Cameron et al. (2022) compared short-term effects of eccentric overload and traditional back squat training over a five-week period in 33 trained males (average age 21.4 ± 2.7 years). They found that while both methods improved eccentric and concentric 1RMs, the eccentric overload group experienced a significantly greater increase in eccentric 1RM (+16.9 kg / 33.3lbs) compared to the traditional group (+12.7 kg / 28lbs). Additionally, the eccentric overload group improved countermovement jump height by 3.8 cm, while the traditional group improved by 2.9 cm (4).
HYPERTROPHY ADAPTATIONS
Overloaded eccentric training has been shown to increase muscle size, but the pattern of hypertrophy appears distinct from concentric training. Research from Friedmann-Bette et al. (2010) suggests that eccentric training induces greater increases in type II fiber cross-sectional area, with subjects experiencing an 8-12% increase over 6 weeks, leading to a faster, more powerful muscle phenotype (5). Douglas et al. (2016) reported that eccentric training increases muscle cross-sectional area (CSA) longitudinally by adding sarcomeres in series, with their study showing a 10-15% increase in muscle length over an 8-week period, potentially leading to greater overall muscle function (6).
MUSCLE DAMAGE AND RECOVERY
A double edge sword of eccentric training is that it can lead to greater muscle damage and soreness, which may increase recovery time and limit training frequency. Roig et al. (2008) found that subjects who performed eccentric-only resistance training experienced 30-40% greater muscle damage markers compared to concentric training, requiring 48-72 hours for full recovery (7). Schoenfeld et al. (2018) reported that trained men performing high-volume eccentric training showed significantly higher delayed onset muscle soreness (DOMS) scores, particularly after workouts exceeding 6-8 sets per muscle group (8). This is particularly relevant for athletes and clients with high training volumes, as excessive soreness can interfere with performance and adherence to a program.
Analysis
In general, the research seems to broadly support the effectiveness of eccentric overload training for increasing both strength and hypertrophy, at least for a novel response compared to traditional training. However, there are important nuances to consider:
More strength and hypertrophy in less time: Studies consistently show greater gains in force production and muscle size compared to traditional training (3)(6).
Improved stretch-shortening cycle efficiency: This has implications for power sports and general athletic performance, as eccentric overload training has been linked to improvements in explosive strength, neuromuscular efficiency, and stretch-shortening cycle efficiency, all of which contribute to enhanced athletic performance (4).
Unique muscle architecture changes: Eccentric overload training appears to encourage longitudinal muscle growth and type II fiber dominance, which can contribute to explosiveness and power output (5).
Greater muscle damage and soreness: Increased recovery time could limit training frequency and overall volume (7).
No superior neural adaptations: Some studies suggest that traditional maximal strength training may be equally effective for neural drive improvements (2).
Accessibility and equipment limitations: While I have access to a Voltra 1 at Verro, many people do not. Without specialized equipment, implementing eccentric overload requires creative solutions, such as manual assistance or weight releasers.
Eccentric training seems to be effective because of its ability to place higher mechanical tension on muscles while recruiting fewer motor units compared to concentric training. This means that muscles experience greater strain at a cellular level. This stimulates hypertrophy and strength adaptations more effectively. Additionally, research suggests that eccentric movements result in greater muscle fiber remodeling, particularly in type II fibers, which are responsible for explosive power. Another possible explanation is that the nervous system adapts uniquely to eccentric overload by improving force absorption and redistribution, enhancing overall athletic performance.
Practical Takeaways
HOW TO IMPLEMENT OVERLOADED ECCENTRICS
For those with access to specialized equipment like the Voltra 1, incorporating eccentric overload is straightforward if you mess with the settings. However, practical alternatives include:
Manual resistance from a training partner (e.g., applying additional pressure during the eccentric phase of a bench press) This method involves a spotter applying extra pressure during the eccentric phase of an exercise, like the bench press, forcing the trainee to control the descent under greater resistance. The partner then reduces resistance for the concentric phase. This method enhances strength and neuromuscular adaptations without requiring specialized equipment. However, it demands a skilled partner for safety. It should be used strategically, especially for advanced lifters.
Eccentric hooks or weight releasers (which allow heavier loads in the eccentric phase)
This method allows lifters to handle heavier loads during the lowering phase of a lift, then automatically release the added weight before the concentric phase. Products like Rogue Weight Releasers are attached to the barbell and disengage at a set height, while weight releasers are designed to drop off at the bottom of the movement. These tools are particularly useful for advanced lifters seeking to overload their eccentric phase without requiring a training partner. However, they necessitate careful programming to avoid excessive fatigue and prolonged recovery times. Also it’s worth noting they only work for the first rep of a set.
IMPORTANT CONSIDERATIONS
Start with moderate overload (10-20% above concentric 1RM) to avoid excessive soreness. Eventually this could be increased to 50%.
Limit frequency to 1-2 sessions per week to allow for adequate recovery and time to adjust to the new training stimulus. As your exposure to heavy eccentrics increases, feel free to add more eccentric sets and sessions.
Conclusion
Eccentric overload training is an effective strategy for enhancing strength and hypertrophy, with research supporting it over traditional methods in many areas, at least for a novel training response in advanced athletes. The key reason for its effectiveness lies in the ability of muscles to generate significantly more force during the eccentric phase, leading to greater mechanical tension and microtrauma, which are critical for muscle growth and strength adaptations.
While tools like the Voltra 1 makes implementation easier, there are practical alternatives for those without access to specialized equipment. The primary downsides are increased muscle damage and recovery demands, which must be managed carefully when integrating eccentrics into a program.
Personally, I plan to continue experimenting with overloaded eccentrics and gradually introduce them into client programs where appropriate. The research suggests that, when applied correctly, they can be a game-changer for strength development by unlocking a level of muscular adaptation that traditional training methods might not fully tap into.
References
Hortobágyi, T., et al. "Effects of Standard and Eccentric Overload Strength Training in Young Women." Medicine & Science in Sports & Exercise, vol. 33, no. 7, 2001, pp. 1206-1212.
Tøien, T., et al. "Maximal Strength Training: The Impact of Eccentric Overload." Journal of Neurophysiology, vol. 120, no. 12, 2018, pp. 2868-2876.
Walker, S., et al. "Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men." Frontiers in Physiology, vol. 7, 2016, article 149.
Cameron, N. M., et al. "Short-Term Effects of Eccentric Overload Versus Traditional Back Squat Training on Strength and Power." International Journal of Kinesiology & Sports Science, vol. 10, no. 1, 2022, pp. 1-8.
Friedmann-Bette, B., et al. "Effects of Strength Training with Eccentric Overload on Muscle Adaptation in Male Athletes." European Journal of Applied Physiology, vol. 108, no. 4, 2010, pp. 821-836.
Douglas, J., et al. "Eccentric Training: Adaptations and Applications for Strength and Conditioning." Sports Medicine, vol. 46, no. 5, 2016, pp. 671-685.
Roig, M., et al. "The Effects of Eccentric Versus Concentric Resistance Training on Muscle Strength and Mass in Healthy Adults: A Systematic Review and Meta-Analysis." Sports Medicine, vol. 38, no. 6, 2008, pp. 547-566.
Schoenfeld, B. J., et al. "Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men." Medicine & Science in Sports & Exercise, vol. 50, no. 1, 2018, pp. 128-138.
Recommended Further Reading and Resources
Horwath, D., et al. "Effects of Eccentric and Concentric Resistance Training on Muscle Hypertrophy and Strength." Journal of Strength and Conditioning Research, vol. 33, no. 2, 2019, pp. 416-426.
Izquierdo, M., et al. "Differential Effects of Strength Training Leading to Failure Versus Not to Failure on Hormonal Responses, Strength, and Muscle Power Gains." Journal of Applied Physiology, vol. 100, no. 5, 2006, pp. 1647-1656.
Núñez, J., et al. "Eccentric Overload Training in Team-Sports Functional Performance: A Systematic Review." International Journal of Sports Physiology and Performance, vol. 13, no. 10, 2018, pp. 1275-1282.
Suchomel, T. J., et al. "The Role of Eccentric Strength in Athletic Performance: A Systematic Review." Sports Medicine, vol. 49, no. 10, 2019, pp. 1629-1645.
Walker, S., et al. "Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men." Frontiers in Physiology, vol. 7, 2016, article 149.
Wang, E., et al. "Eccentric Resistance Training for Aging Skeletal Muscle: A Systematic Review and Meta-Analysis." Journal of Aging and Physical Activity, vol. 32, no. 1, 2024, pp. 1-14.
DISCLAIMER
This article is for informational and educational purposes only and is not a substitute for medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider or certified fitness professional before starting any new training program, especially if you have any pre-existing health conditions or injuries. Individual results may vary, and adjustments to training volume, exercise selection, and intensity should be made based on your personal recovery capacity, experience level, and goals.